1. Field of the Invention
The present invention relates particularly to organic coating compositions useful for both permanent and temporary protection of metal part such as cold rolled steel. More particularly, the organic coating compositions of this invention generally are classified 106, particularly in subclasses 14.11, 14.13, 14.15, 14.16, 14.34, 14.35, 14.37, 14.38, 270, 271, and 272.
2. Description of the Prior Art
Yaroshevich U.S. Pat. No. 3,539,367 et al discloses a wax emulsion containing a salt of an organic acid and an amine. Shedahl U.S. Pat. No. 3,660,128 teaches an alkanolamine and an aliphatic carboxylic acid in the preparation of a semi-solid wax-in-water emulsion. Wilson U.S. Pat. No. 2,349,326 teaches a combination of morpholine and a fatty acid to emulsify waxy materials in water for paste-type waxes. Simmonds U.S. Pat. No. 3,125,453 employs a mixture of triethanolamine and an acid to emulsify a mixture of waxes also for paste-type polishes.
Davis U.S. Pat. No. 4035,514 teaches a water-dispersible petrolatum composition containing cetyl alcohol, lanolin alcohols and alkoxylate fatty acids esters of sorbitol.
Most of the above teach production of temporary coatings such as floor waxes, cosmetics and the like. In contrast, the present invention, possibly through the use of co-solvents which tend to form azeotropes which enhance water removal during curing, provides coatings having substantial life even in corrosive environments. While not wishing to be bound to any theory or mechanism, it appears the co-solvents tend to act as dispersing agents and additionally enhance stability of the liquid compositions at low temperatures.
Also, the inclusion of the salts of organic acids in the present invention tend to build longer-chain molecules which additionally deter corrosion and promote stability.
The coatings of the present invention find additional utility as lubricants, e.g. particularly for wire drawing and other metal drawing, extrusion and impact forming operations.
In brief review, other prior U.S. patents of interest include: Yaroschevich U.S. Pat. No. 3,539,367 relates to cationic emulsions (the compositions of the present invention are not cationic emulsions);
Sheldahl U.S. Pat. No. 3,660,128 relates to inverted wax emulsion pastes for artwork;
Wilson U.S. Pat. No. 2,349,326 and Simmonds U.S. Pat. No. 3,125,453 both relate to paste-type polishes;
Westlund et al U.S. Pat. No. 2,862,825, Saywell U.S. Pat. No. 2,943,945 and Kassinger U.S. Pat. No. 3,565,843 all relate to soluble oils not to firm wax coatings;
Miller U.S. Pat. No. 3,434,851 relates to solvent-borne asphalt coatings;
Phillips U.S. Pat. Nos. 3,446,765, Clark U.S. Pat. No. 3,699,065, Scheurman III U.S. Pat No. 4,184,991 Bottom U.S. Pat. No. 3,223,666, Jen U.S. Pat. No. 3,379,548, Hunsucker U.S. Pat. No. 4,039,495, Tobias U.S. Pat. No. 4,051,089 and Hunsucker U.S. Pat. No. 4,081,441, all relate to base resin formulas not to completed coatings; Tobias U.S. Pat. No. 4,051,089 to Tobias and Tobias U.S. Pat. No. 4,051,089 to Tobias and
Andrews U.S. Pat. No. 3,494,882, relate to high gloss emulsified polyester emulsions; Tobias U.S. Pat. No. 4,051,089 to Tobias and
Howard U.S. Pat. No. 4,187,204, relates to water-borne paint containing not over 10% water;
Vosishth and Wang U.S. Pat. No. 4,225,477, relate to co-solvent changes in water-borne coatings to control re-coatability (the coating's ability to form a substrate for a topcoat);
Williams U.S. Pat. No. 4,148,948relate to a leveling additive for water dispersible paints; and
Howard and Randell U.S. Pat. No. 3,413,227, relate to substituted benzotriazole.
Other patents considered in preparing this application are:
Storck, et al U.S. Pat. No. 3,879,335, PA0 Asseff, P. A., et al U.S. Pat. No. 2,695,910, PA0 Johnson, et al U.S. Pat. No. 3,565,678, PA0 Marshall, et al U.S. Patent No. 4,239,648, PA0 Nishijima, et al U.S. Pat. No. 4,059,452, PA0 Burchart, et al U.S. Pat. No. 3,653,931, PA0 Chan, et al U.S. Pat. No. 3,985,584, PA0 Kotzach, et al U.S. Pat. No. 4,048,374, PA0 Carreny, L. U.S. Pat. No. 3,839,051, PA0 Delcon, et al U.S. Pat. No. 3,903,346, PA0 Yalloorakis, M. D. U.S. Pat. No. 3,864,322, PA0 Hung, T. M. U.S. Pat. No. 4,062,821, PA0 Tomalia, D. A. U.S. Pat. No. 3,773,550, PA0 Davis, R. I. U.S. Pat. No. 4,035,514, PA0 Gillich, T. N. U.S. Pat. No. 4,162,920, PA0 Erby, et al U.S. Pat. No. 3,661,796, PA0 Wollak, et al U.S. Pat. No. 3,313,635, PA0 Fessler, et al U.S. Pat. No. 8,080,221, PA0 Jarvis, W. H. U.S. Pat. No. 3,738,851, PA0 Johnson, K. L. U.S. Pat. No. 3,726,807, PA0 Northan et al. U.S. Pat. No. 3,642,653,
Problems with protective coatings for metals, especially those primarily intended for long-term storage protection, have always existed. Prominent difficulties have been tackiness, poor water removability, sensitivity to water, objectionable odor, and, where water-borne compositions are involved, limited high-temperature storage stability of the compositions themselves.
In general, the main benefit of a water reducible coating is that it reduces the amount of organic volatiles that are given off during a coating process. Another advantage is that use of such materials is safer both for people and for the environment.
Any water reducible composition involving an emulsion must have sufficient storage stability in order to have practical commercial applications For example, a drum of a water reducible emulsion must remain homogeneous for a sufficient amount of time after packaging to permit use by an end use customer, who in turn may have to store the drum in this inventory prior to his use.
It is an object of this invention to provide a sufficiently stable emulsion to have a storage life of at least 6 months when subjected to storage temperatures in the range of 50-90.degree. F. (10-32.degree. C.).
It is an object of this invention to provide a composition suitable for use in airless spray-type equipment such as 17:1 ratio pump sold by Graco and Alemite, etc.
It is a further object of this invention to provide an emulsion composition which can be used in "dip coating" operations. A "dip coating operation" for purpose of this specification involves the process of immersing a part to be coated totally within the composition, removing, and allowing any excess to drip off or flow off from the part, thereby forming a protective film coating thereon.
It is still another object of this invention to provide a coating composition which when formed into a film yields a film which can be both permanent or easily removed. By "easily removed" is meant for purposes of this invention removal by water at a temperature of at least 160.degree. F. (71.degree. C.).
It is another object of this invention to provide a composition that yields a film which provides permanent protection in that it has sufficient water resistance that mere contact with water under ordinary circumstances up to a temperature of 120.degree. F. (49.degree. C.) will not dissolve (situations wherein the film becomes undesirable for its purpose of protection).
It is still another object of this invention to provide both salt spray (ASTM B-117 corrosion test) and humidity protection (ASTM D-1748) in excess o what would otherwise be available in the prior art of any soft film forming water-borne emulsion coating composition.
It is still another object of this invention to provide an emulsion composition for coatings having a Brookfield viscosity according to ASTM D-2196 of about 20,000 cps at 2 rpm to about 30,000 cps both at 77.degree. F. (25.degree. C.) temperature.
Other objects of this invention will be clear to those of skill in the art based upon this specification.